General Obstetrics and Gynecology: ObstetricsPrediction of severe fetal anemia in red blood cell alloimmunization after previous intrauterine transfusions
Section snippets
Material and methods
In our center, in the management of red blood cell alloimmunized pregnancies, the decision for fetal blood sampling and measurement of fetal Hb concentration is based on the finding that the fetal MCA-PSV is 1.5 SD or more above the expected mean for gestational age.15 An intrauterine intravascular transfusion with donor blood, crossed matched with the mother, is given if the fetal Hb concentration is below the 5th percentile of the normal range for gestation. Subsequently, patients are
Statistical analysis
In each case, the measured MCA-PSV and pretransfusion Hb concentration were expressed as delta values (difference in SDs from the respective normal mean for gestation).2, 15 Moderate/severe anemia was defined as Hb deficit 4 g/dL or greater, and severe anemia as Hb deficit 6 g/dL or greater, according to the expected mean for gestational age. The daily rate of decrease in fetal Hb concentration was calculated by dividing the difference between the posttransfusion Hb of the previous transfusion
Results
The maternal hemolytic antibodies in the red blood cell alloimmunized pregnancies are shown in Table I. The median gestation at the second transfusion was 28 (range 20-34) weeks and at the third transfusion was 30 (range 23-34) weeks. The fetal pretransfusion Hb concentration at the second transfusion was 4 g/dL or greater and 6 g/dL or greater below the normal mean for gestation in 28 (66.7%) and 12 (28.6%), respectively, of the 42 cases. The fetal pretransfusion Hb concentration at the third
Comment
The data of this study demonstrate that, in red blood cell alloimmunized pregnancies, the prediction of severe and/or moderate fetal anemia by MCA-PSV is less accurate in those cases that had already been treated by intrauterine blood transfusions than in those that had not been transfused. The FPR for detection of at least 95% of severely anemic fetuses by MCA-PSV was about 14% for the first transfusion, 37% for the second and 90% for the third (Table V). Alternatively, at the FPR of 15% the
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Cited by (77)
Effect of delayed cord clamping on red blood cell alloimmunization: a retrospective cohort study
2023, American Journal of Obstetrics and Gynecology MFMPractice patterns amongst fetal centers performing intrauterine transfusions (PACT): An international survey study
2022, European Journal of Obstetrics and Gynecology and Reproductive BiologyCitation Excerpt :Cases of HDFN require multiple IUTs due to hemolysis resulting from incompatibility between maternal and fetal blood, this expected drop in the H/H each day after the transfusion has been reported. The interval between transfusion is determined either by elevated MCA PSV or expected drop in fetal hemoglobin [15–17]. With increasing number of transfusions and advancing gestational age, the MCA PSV is less reliable, however, no significant differences were noted when either technique was utilized [15].
The rate of decline in fetal hemoglobin following intrauterine blood transfusion in the management of red cell alloimmunization
2022, European Journal of Obstetrics and Gynecology and Reproductive BiologyCitation Excerpt :Current guidelines recommend performing fetal blood sampling to obtain a definitive diagnosis once the MCA-PSV threshold of 1.5 MoM is reached [10]. While the MCA-PSV has been shown to be a useful tool for identifying a fetus with ‘moderate-severe’ anemia prior to their first IUT [4,5,7,18], evidence is conflicting as to whether measuring the MCA-PSV is as effective in a previously transfused fetus [19–21]. The objective of this study was to improve our ability to predict the response to a transfusion in utero.
Peak systolic velocity of fetal middle cerebral artery to predict anemia in Red Cell Alloimmunization in un-transfused and transfused fetuses
2021, European Journal of Obstetrics and Gynecology and Reproductive BiologyCitation Excerpt :After an initial transfusion, using a cut-off for MCA-PSV higher than 1.5 MoM for diagnosing fetal anemia requiring subsequent IUT was proposed by several authors [18,25,26]. On the other hand, other authors including Scheier et al. recommend a decision of timing subsequent procedures based on the hemoglobin level at the end of the previous transfusion and on the expected daily decrease in fetal hemoglobin (Hb) [27]. Small number of studies have compared MCA-PSV to Hb decline rates in the determining the optimum procedure to be performed.
The utility of MRI for measuring hematocrit in fetal anemia
2020, American Journal of Obstetrics and GynecologyFetal anemia: Diagnosis and management
2019, Best Practice and Research: Clinical Obstetrics and GynaecologyCitation Excerpt :The use of MCA-PSV to predict fetal anemia becomes less reliable after several intrauterine transfusions, with false-positive rates of 14%, 37%, and 90% for the detection of 95% of severely anemic fetuses following the first, second, and third intrauterine transfusions, respectively [36]. In anemic fetuses, the increase in MCA-PSV reflects a hyperdynamic circulation because of decreased blood viscosity; following intrauterine transfusion with adult blood cells, which have a lower viscosity, the use of MCA-PSV to predict fetal anemia becomes less reliable [36]. For the same reasons, false-positive results are also more frequent at 34–37 weeks in the case of previous intrauterine transfusion [24].
Supported by the Fetal Medicine Foundation (Registered Charity 1037116).
Reprints not available from the authors.